Uploadify HTTP 302 error and IO error in PHP Codeigniter

Question

I Try to integrate my Codeigniter web with uploadify. its work fine in Chrome and even IE, but getting HTTP 302 error when I run my web in Mozilla firefox. and sometimes its show "IO Error" too, I read this post: 302 and IO uploadify error, but still doesnt have idea what I must to do. maybe more detail/clear guide would be help.

this is my uploadify config in view:

$('#shopfile').uploadify({
            'debug':false,
            'auto':true,
            'swf': '<?= base_url(); ?>file/lib/uploadify/uploadify.swf',
            'uploader': '<?= base_url(); ?>my_shop/upload_shopheader',
            'cancelImg': '<?= base_url(); ?>file/lib/uploadify/uploadify-cancel.png',
            'fileTypeExts':'*.jpg;*.jpeg;*.png;',
            'fileTypeDesc':'Image Files (.jpg,.jpeg,.png)',
            'fileSizeLimit':'2MB',
            'fileObjName':'shopfile',
            'buttonText':'Select File',
            'multi':false,
            'removeCompleted':false,
            'onUploadError' : function(file, errorCode, errorMsg, errorString) {
                alert('The file ' + file.name + ' could not be uploaded: ' + errorString);
                $( ".uploadMessageStr" ).html('<div class="alert alert-danger">The file ' + file.name + ' could not be uploaded: ' + errorString + '</div>');
            },
            'onUploadSuccess' : function(file, data, response){
                //some statement..
            }
        });

and this is my controller / uploader function code :

public function upload_shopheader(){
    if (empty($_FILES['shopfile']['name'])) redirect('my_shop/profile');

    $config = $this->avatarUploadConfig();
    $this->upload->initialize($config);
    $data = array();

    if (!$this->upload->do_upload('shopfile')) { 
        //if upload failed...
        $upload_error = $this->upload->display_errors();
        $data['message'] = "<div class='alert alert-danger'>Upload Failed. ".$upload_error."</div>";
    } 
    else { 
        //if upload success...
    }

    echo json_encode($data);
}

Thanks before.

Answer 1

SOLVED with add session id manually through uploadify.

adding this to uploadify config in view:

'formData' : {'SESSION_ID' : '<?= $this->session->userdata('session_id'); ?>'},

and add this code in beginning of controller function:

//check session..
    $sess_id = $this->input->post('SESSION_ID');
    if(!isset($sess_id)){
        redirect('to_some/page');
    }
    else{
        $this->session->set_userdata(array('session_id' => $sess_id));
    }